Experimental aflatoxin production in Manchego-type cheese

Area of Science:

• Food Science and Technology
• Mycology
• Food Safety

Background:

• Aflatoxins are toxic secondary metabolites produced by Aspergillus species.
• Manchego-type cheese is a popular Spanish cheese susceptible to microbial contamination.
• Controlling aflatoxin contamination in cheese is crucial for public health.

Purpose of the Study:

• To investigate the efficacy of paraffin coating in preventing aflatoxin production in Manchego-type cheese.
• To determine the influence of inoculation site and temperature on aflatoxin formation by Aspergillus parasiticus.

Main Methods:

• Manchego-type cheese was inoculated with Aspergillus parasiticus NRRL 2999 via milk contamination, surface inoculation, center inoculation, or cheese portion inoculation.
• Cheeses were treated with or without paraffin coating and ripened under various temperature conditions (10, 15, and 28 degrees C).
• Aflatoxin levels and fungal growth were monitored over time using HPLC and visual inspection.

Main Results:

• Paraffin coating significantly inhibited aflatoxin detection in cheeses inoculated via milk or surface methods.
• Aflatoxin production was temperature-dependent, with the highest levels (132 µg/g) detected at 28 degrees C.
• At 10 degrees C, heavy fungal growth occurred, but no aflatoxins were detected, suggesting temperature affects toxinogenesis.

Conclusions:

• Paraffin wax is an effective barrier against Aspergillus parasiticus invasion and subsequent aflatoxin contamination in Manchego-type cheese.
• Lower ripening temperatures (10 degrees C) inhibit aflatoxin production despite fungal growth.
• Strategic application of paraffin coating and controlled ripening temperatures are vital for ensuring cheese safety.